Group alignment of solar concentrator micro-mirrors

Abstract

Due to an ever growing shortage of conventional energy sources, there is an increasingly intense interest in harnessing solar energy. The instant invention is concerned with method and apparatus for the group alignment of solar concentrator micro-mirrors and the maximization of the percentage of incident light that is reflected to the receiver. Novel method and apparatus are taught for the alignment in large groups or ensembles of micro-mirrors of a micro-optics solar concentrator system for single-axis and two-axis tracking. Broadly this invention deals with novel concepts used for alignment in the focussing of light wherever mirrors are used for focussing such as for solar propulsion assist, illumination and projection of light, optical switching, etc. A particularly important objective is the focussing of sunlight for solar power conversion and production. The instant invention can contribute to the goal of achieving environmentally clean solar energy on a large enough scale to be competitive with conventional energy sources.

1. An electric assembly for a micro-optics solar concentrator, the apparatus comprising:
 a) an array of micro-mirrors rotatably disposed in a substrate; 
 b) electric dipoles in said rotatable micro-mirrors; 
 c) said apparatus having a plurality of addressable elements; 
 d) two bus bars connected to opposite poles of a voltage source; 
 e) at least two sets of opposite rung electrodes which interlace orthogonally within each plane, and criss-cross each other and are separated by dielectrics; 
 f) said rung electrodes electrically connected to at least two of said bus bars for electric field group coupling to said electric dipoles by means of said voltage source; and 
 g) microprocessor means for selectively addressing each pair of said bus bars. 
 
     
     
       2. The apparatus of  claim 1 , wherein there are at least three independent voltage sources connected to at least three pairs of rung electrodes. 
     
     
       3. The apparatus of  claim 1 , wherein said array of micro-mirrors are disposed between a top transparent electrode opposite a bottom electrode connected to an independent voltage source. 
     
     
       4. The apparatus of  claim 1 , wherein said array of micro-mirrors are disposed between a top grid electrode opposite a bottom electrode connected to an independent voltage source. 
     
     
       5. The apparatus of  claim 1 , wherein said electric dipoles are induced in each of said micro-mirrors by said electric field. 
     
     
       6. The apparatus of  claim 1 , wherein an electret is placed adjacent to each micro-mirror so that its permanent electric dipole is parallel to said electric dipole. 
     
     
       7. The apparatus of  claim 1 , wherein a group of said micro-mirrors are given the same alignment. 
     
     
       8. A method of aligning groups of an array of rotatable mini-mirrors in a light modulating apparatus comprising the steps of:
 a) selectively inducing an electric dipole in each of said rotatable mini-mirrors; 
 b) producing a grid array of independently orientable electric fields for coupling to the induced electric dipoles by means of sets of orthogonally criss-crossing opposing rung electrodes; and 
 c) selectively aligning at least one of said rotatable mini-mirrors by means of said electric fields. 
 
     
     
       9. The method of  claim 8  further comprising the step of applying at least three independent voltages to at least three pairs of rung electrodes. 
     
     
       10. The method of  claim 8  further comprising the step of placing an electret adjacent to each mini-mirror so that its permanent electric dipole is parallel to said induced electric dipole. 
     
     
       11. The method of  claim 8  further comprising the step of energizing a top transparent electrode opposite a bottom electrode connected to an independent voltage source, between which electrodes are disposed in said array of micro-mirrors. 
     
     
       12. The method of  claim 8  further comprising the step of energizing a top grid electrode opposite a bottom electrode connected to an independent voltage source, between which electrodes are disposed in said array of micro-mirrors. 
     
     
       13. The method of  claim 8  further comprising the step of giving said mini-mirrors the same alignment as a group. 
     
     
       14. Apparatus for focussing and directing reflected light comprising:
 a) an array of micro-mirrors rotatably disposed in a substrate; 
 b) electric dipoles in said rotatable micro-mirrors; 
 c) said apparatus having a plurality of addressable elements; 
 d) two bus bars connected to opposite poles of a voltage source; 
 e) at least two sets of orthogonally criss-crossing rung electrodes electrically connected to at least two of said bus bars for electric field group coupling to said electric dipoles; and 
 f) microprocessor means for selectively addressing each pair of said bus bars; and 
 g) means for selectively establishing independent voltage differences between each pair of said bus bars by means of said voltage source. 
 
     
     
       15. The apparatus of  claim 14 , wherein there are at least three independent voltage sources connected to at least three pairs of rung electrodes. 
     
     
       16. The apparatus of  claim 14 , wherein said array of micro-mirrors are disposed between a top transparent electrode opposite a bottom electrode connected to an independent voltage source. 
     
     
       17. The apparatus of  claim 14 , wherein said array of micro-mirrors are disposed between a top grid electrode opposite a bottom electrode connected to an independent voltage source. 
     
     
       18. The apparatus of  claim 14 , wherein said electric dipoles are induced in each of said micro-mirrors by said electric field. 
     
     
       19. The apparatus of  claim 14 , wherein an electret is placed adjacent to each micro-mirror so that its permanent electric dipole is parallel to said electric dipole. 
     
     
       20. The apparatus of  claim 14 , wherein a group of said micro mirrors are given a small optical concavity.